The birthday (er, belated birthday) girl was sporting cornrows and a pair of oversize aviator sunglasses for her dip in the ocean—naturally—and joked around with pals as they took turns splashing each other in the waves.

"As they climbed off the Wave Runner, Tyga helped Kylie balance and held her around her waist so that she could get on safely. They climbed aboard with a few friends and headed up to the bow of the boat. They sat on the front as they cruised around and went for a ride. Kylie was laying in between Tyga's legs and resting up against him…Everyone was having an amazing time and the best day."